The firm that screens baggage at San Francisco International Airport could lose its decadelong contract this fall as the Transportation Security Administration requests proposals from other bidders two years ahead of when the contract was originally supposed to expire.

Covenant Aviation Security, America’s most prominent private aviation security company, has a national reputation for efficiency and customer service. But it also has been accused of neglecting passenger safety in pursuit of lower costs.

Last summer, The San Francisco Examiner documented numerous worker allegations about high-risk bags being routinely loaded onto planes at SFO each day without any human inspection. When The San Francisco Examiner published its findings, Covenant denied the allegations, although Transportation Security Administration spokesman Nico Melendez confirmed that his agency had received numerous complaints from whistle-blowers.

Company representatives declined to comment for this article. But San Mateo County Central Labor Council Executive Secretary Shelley Kessler said she understands that the federal agency’s contract review is motivated by a desire to cut costs further.

“My understanding is … they’re assessing what expenditures can be eliminated,” she said.

In spite of the criticism that some employees have directed at Covenant, Kessler said the prospect of a new security provider has rattled many of the workers who watch bags glide through SFO’s X-ray machines each day. Kessler worried that a sudden change in leadership might undermine years of lobbying for a living wage and decent working conditions by employees and union organizers.

“We want to make sure that people are compensated fairly and that they can afford to live in the Bay Area,” she said.

Kessler noted that airport screening is a mind-numbing job, but said that shouldn’t detract from its importance to the people who stream through SFO’s security gates each day.

Airport officials began emphasizing high-quality working conditions in 2000, when they adopted a quality standards program for hiring practices, equipment and wages. The current $19.67 hourly wage for screeners exceeds the wages paid by TSA at other airports. That’s partly a result of the Transportation Security Administration outsourcing its managerial duties to private companies, Kessler said.

Indeed, SFO is the nation’s largest privately protected airport, and a poster child for the privatization of aviation security. Kessler called privatization a boon for airport employees. It’s allowed for an hourly wage that better reflects the cost of living in the Bay Area.

She and other union representatives worry that a new contractor might abandon that high standard and also ignore the airport’s current pension policy. They fear that any budget trimming might compel a mass exodus.

Northern California airport division coordinator Jamie Thompson said labor advocates at the Service Employees International Union are trying to stave off “a return to the unacceptable pre-9/11 workforce practices.”

A spokesman for the Transportation Security Administration said the agency is rebidding Covenant’s SFO contract earlier than its original 2015 expiration date because the contract requirements have changed.